The invention is based on a priority application EP 04 360 052.7 which is hereby incorporated by reference.
This invention relates to a telephone message forwarding method and a resident telephone device. The method is used for an automatic handover from a mobile telephone handset to another telecommunication set, preferably a resident mobile telephone device in a car to avoid the use of a hand held cellular phone by a driver of the car.
In many countries a hand free telephone device is legally requested for using a cellular telephone in a car, meaning any motor vehicle e.g. a passenger car, a bus or a truck, by the driver of the car.
Known hand free telephone devices are specifically designed to be used by a specific type of a cellular telephone. Furthermore, they are adapted to be installed in specific types of cars. Thus, if a person changes his car or his cellular telephone he also has to change the hand free telephone device.
To avoid these problems cars having installed a resident cellular telephone device using an own Subscriber Identity Module (SIM) Card and having associated an own telephone number are known. Therefore, the owner of the car has to pay telephone charges for his cellular telephone and the resident cellular telephone device in his car. Disadvantageously, a caller trying to call said owner has to try twice to reach the owner, in case the owner is driving his car.
Alternatively, there is the possibility to use a double SIM Card. In this case, the cellular telephone has to be switched off when the owner enters his car and to be switched on again when he exits the car, for redirecting incoming calls respectively, which is an inconvenient procedure.
Furthermore, it depends on the owner (user) himself whether he is willing to use the resident cellular telephone device or not. Therefore, the legally requested usage of a hand free device cannot be ensured.